Fair Value of Assets and Liabilities (Narrative) (Details) (USD $)	6 Months Ended
Jun. 30, 2012	Jun. 30, 2013	Dec. 31, 2012
Total commercial mortgage and other loans		$ 1,507,446,000	$ 1,463,977,000
Other Long-Term Investments		168,607,000	284,489,000
Other liabilities		906,838,000	726,737,000
Embedded Derivative Fair Value of Embedded Derivative		(344,000,000)	1,441,000,000
Separate Account Assets Invested In Real Estate		78,400,000
Derivative With Fair Value		0	200,000
Equity Securities, AFS Transfered From Level 1 To Level 2	$ 8,600,000
High Range [Member]
Capitalization Rates		9.50%
Discount Rates		11.80%
Low Range [Member]
Capitalization Rates		5.00%
Discount Rates		7.00%
Weighted Average Rate [Member]
Capitalization Rates		7.00%
Discount Rates		8.20%

Net fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as assets, net of those classified as liabilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 12-16, 44A, 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A, 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44B

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details